feat: add Astro-specific review rules (#289)

internal/config/rules/rule_docs/astro.md

@@ -0,0 +1,45 @@
+#### Obvious Typos or Spelling Errors
+- Spelling errors in component names, props, slots, or user-facing strings that affect readability
+
+#### Dead Code
+- Unused islands, framework components, scripts, or template branches that add client cost without affecting rendered behavior
+
+#### Astro Component Boundaries
+- When frontmatter data reaches client HTML, inline scripts, or hydrated islands, verify whether it was computed at build time or request time and whether exposing non-`PUBLIC_` env values, cookies, headers, sessions, `Astro.locals`, secrets, request-only data, or server-only APIs is intentional
+- Flag `.astro` templates that appear to assume frontmatter values are reactive in the browser
+- Flag framework components used only to render static markup when plain Astro markup would avoid unnecessary client JavaScript
+
+#### Hydration and Islands
+- `client:*` applies only to directly imported UI framework components, not `.astro` components or dynamic tags
+- Flag `client:load` on non-critical UI, missed `client:idle` or `client:visible` opportunities, `client:media` where the media query does not actually gate the interaction need, and over-hydration from large or overly numerous islands
+- Flag `client:only` without the framework string or without fallback content when the result is blank or confusing pre-hydration UI
+
+#### Server-to-Client Data Transfer
+- Flag hydrated framework component props or server-fetched data passed client-side without reducing to the minimal interaction payload; props crossing hydrated boundaries must use Astro-supported serializable types, so flag functions, class instances, circular objects, secrets, and unnecessarily large payloads.
+- `<script define:vars>` values are JSON-stringified and inline; flag secrets, large payloads, or repeated per-instance duplication
+
+#### Server Islands
+- Flag `server:defer` usage without required adapter support or without a fallback slot when deferred content needs a meaningful loading state
+- Props passed into `server:defer` islands must use Astro-supported serializable types; flag functions, circular objects, secrets, and large request objects
+- Flag `server:defer` uses that leak request-specific data into cacheable output or weaken privacy assumptions
+
+#### Template Safety
+- Treat `set:html` as a high-risk escape hatch; flag it unless the source is clearly trusted or sanitized
+- Flag unsafe or insufficiently validated dynamic values inserted into attributes, URLs, or raw markup
+- Flag fragile template structures, especially mixed `set:*` usage or conditional markup that changes HTML shape in surprising ways
+
+#### Scripts
+- Flag scripts with attributes other than `src` when unprocessed behavior causes avoidable per-instance duplication, bypasses bundling, or relies on server-only values
+- Flag framework hydration used for behavior that a small processed Astro script would handle
+
+#### Styles
+- Flag unnecessary `is:global` usage when scoped styles or a narrow `:global(...)` escape would do
+- Flag selectors that assume scoped CSS can style child component internals across a component boundary
+- Flag components that accept parent styling but fail to forward `class` and needed rest props
+
+#### Content and Assets
+- For structured Markdown/MDX/JSON content, flag ad hoc loading when Astro content collections would materially improve schema validation, typing, or route generation
+- Flag plain `<img>` or `public/` asset usage when the implementation appears to expect Astro image optimization, responsive behavior, fingerprinting, transforms, or import-time validation
+
+#### Markup and Accessibility
+- Flag non-semantic or fragile interactive markup, including inaccessible islands before hydration, invalid conditional HTML, or mixed Astro/framework composition that breaks keyboard or focus behavior

internal/config/rules/system_rules.json

@@ -13,6 +13,7 @@
     "**/*.{yaml,yml}": "yaml.md",
     "**/*.java": "java.md",
     "**/*.ets": "arkts.md",
+    "**/*.astro": "astro.md",
     "**/*.{ts,js,tsx,jsx}": "ts_js_tsx_jsx.md",
     "**/*.{kt}": "kotlin.md",
     "**/*.rs": "rust.md",

internal/config/rules/system_rules_test.go

@@ -67,6 +67,7 @@ func TestResolve_DefaultRules(t *testing.T) {
 		{"frontend/package.json", "latest"},
 		{"config/app.yaml", "yaml-key"},
 		{"deploy/values.yml", "yaml-key"},
+		{"src/pages/index.astro", "client:*"},
 		{"src/components/app.tsx", "React"},
 		{"lib/utils.ts", "TypeScript"},
 		{"app.kt", "Null Safety"},
@@ -157,12 +158,23 @@ func TestResolve_CaseInsensitive(t *testing.T) {
 	rule := &SystemRule{
 		DefaultRule: "default",
 		PathRules: []PathRule{
+			{Pattern: "**/*.astro", Rule: "astro-rule"},
 			{Pattern: "**/*.java", Rule: "java-rule"},
 			{Pattern: "**/Cargo.toml", Rule: "cargo-rule"},
 		},
 	}
 
-	got := rule.Resolve("Foo.Java")
+	got := rule.Resolve("Foo.Astro")
+	if got != "astro-rule" {
+		t.Errorf("expected astro-rule for uppercase extension, got %q", got)
+	}
+
+	got = rule.Resolve("foo.astro")
+	if got != "astro-rule" {
+		t.Errorf("expected astro-rule for lowercase, got %q", got)
+	}
+
+	got = rule.Resolve("Foo.Java")
 	if got != "java-rule" {
 		t.Errorf("expected java-rule for uppercase extension, got %q", got)
 	}